Defects in pharmaceutical products can be highly dangerous, or even fatal. And even if such defects are relatively minor, such as non-uniformly sized capsules, they can result in a significant loss of goodwill by the manufacturer. It is therefore of the utmost importance to avoid such defects.
Several approaches now exist to screen pharmaceutical agents packaged in predetermined dosage units, such as capsules or tablets. These include off-line and on-line methods. Off-line methods include the testing of samples of reagents and end-products using various analytical methods. On-line methods attempt to monitor the process of manufacturing the product to detect defects as they occur.
A number of on-line screening approaches currently exist. One approach includes adding coloring agents to bulk ingredients and optically checking the shape, integrity, and color of the final product. Systems employing this approach can take a series of video images of dosage units and use image processing methods to assess the shape and color of the dosage units. Other systems employ groups of discrete optical detectors to detect different colors and infrared detectors to detect the scattering caused by structural defects. These systems can be complicated to install and maintain, and cannot guarantee a defect-free product.